package coordinator

import (
	"errors"
	"sync"
	"sync/atomic"
	"testing"
)

func TestContextUpdateConcurrentNoLostUpdate(t *testing.T) {
	ctx := &UserProjectContext{
		Version:         1,
		BlackboardFacts: map[string]string{"market": "国内"},
	}
	var ok, stale int32
	var wg sync.WaitGroup
	for i := 0; i < 2; i++ {
		wg.Add(1)
		go func(label string) {
			defer wg.Done()
			err := ApplyContextUpdate(ctx, ContextUpdate{
				ExpectedVersion: 1,
				BlackboardSet:   map[string]string{"market": label},
			})
			switch {
			case err == nil:
				atomic.AddInt32(&ok, 1)
			case errors.Is(err, ErrStaleContext):
				atomic.AddInt32(&stale, 1)
			default:
				t.Errorf("unexpected %v", err)
			}
		}("v" + string(rune('a'+i)))
	}
	wg.Wait()
	if ok != 1 || stale != 1 {
		t.Fatalf("ok=%d stale=%d version=%d facts=%v", ok, stale, ctx.Version, ctx.BlackboardFacts)
	}
	if ctx.Version != 2 {
		t.Fatalf("version %d", ctx.Version)
	}
	if ctx.BlackboardFacts["market"] == "国内" {
		t.Fatal("winner did not apply")
	}
}

func TestContextUpdateFillDoesNotOverwrite(t *testing.T) {
	ctx := &UserProjectContext{Version: 0, BlackboardFacts: map[string]string{"a": "1"}}
	if err := ApplyContextUpdate(ctx, ContextUpdate{ExpectedVersion: 0, BlackboardFill: map[string]string{"a": "x", "b": "2"}}); err != nil {
		t.Fatal(err)
	}
	if ctx.BlackboardFacts["a"] != "1" || ctx.BlackboardFacts["b"] != "2" {
		t.Fatalf("%v", ctx.BlackboardFacts)
	}
}